1. Which unit is equivalent to J kg−1?
2. A velocity of 5 ms−1 can be resolved along perpendicular directions XY and XZ.
The component of the velocity in the direction XY is of magnitude 4 ms−1. What is the magnitude of the component in the direction XZ?
A. 4 m s−1
B. 3 m s−1
C. 2 m s−1
D. 1 m s−1
3. A tennis ball is released from rest and falls vertically through a small distance in air. What is the change in the speed of the ball and the change in the acceleration of the ball as it falls?
4. The graph below shows the variation with time t of the velocity v of a car travelling in a straight line.
Which graph shows the variation with t of the displacement s of the car?
5. Which statement applies to an object in translational equilibrium?
A. The object must be stationary.
B. The object must be moving with constant acceleration.
C. The resultant force acting on the object must be zero.
D. There must be no external forces acting on the object.
6. A constant horizontal force F is applied to a block Y. Block Y is in contact with a separate block X.
The blocks remain in contact as they accelerate along a horizontal frictionless surface. Y has a greater mass than X. Air resistance is negligible.Which statement is correct?
A. The force F is equal to the product of the mass of Y and the acceleration of Y.
B. The force that Y exerts on X is less than F.
C. The force that Y exerts on X is less than the force that X exerts on Y.
D. The force that Y exerts on X is equal to F.
7. Two identical spheres, each of mass m and speed v, travel towards each other on a frictionless surface in a vacuum.
The spheres undergo a head-on elastic collision.Which statement correctly describes the spheres after the collision?
A. The total momentum of the spheres is 2mv.
B. Each sphere has zero momentum.
C. The total kinetic energy of the spheres is mv2.
D. Each sphere has zero kinetic energy.
8. A mass is suspended by a string from a fixed point. The mass moves with constant speed along a circular path in a horizontal plane.
The resultant force acting on the mass is
B. directed upwards along the string.
C. directed towards the centre of the circular path.
D. in the same direction as the velocity of the mass.
9. What is the definition of the mole?
A. The amount of substance that has the same mass as 6.02 × 1023 atoms of carbon-12.
B. The amount of substance that contains as many nuclei as the number of nuclei in 12 g of carbon-12.
C. The amount of substance that has the same mass as one atom of carbon-12.
D. The amount of substance that contains as many elementary entities as the number of atoms in 12 g of carbon-12.
10. Molecules leave a boiling liquid to form a vapour. The vapour and the liquid have the same temperature.What is the change of the average potential energy and the change of the average random kinetic energy of these molecules when they move from the liquid to the vapour?